Are preschoolers really lighter?

The HealthGal Health Guide
  • Headlines screamed a plunge in preschool obesity during the last week of February, and almost every news and health organization grabbed on to this beacon of hope.  In fact, the news coverage may not have been spot on.  Reports initially suggested that the rates of obesity among two to five year olds dropped from 13.9 percent to 8.4 percent, during the years of 2003 and 2012.  One epidemiologist suggested a glimmer of hope, and personally acknowledged that the rapid increase of obesity seen in the 1980’s and the 1990s had “definitely slowed.”  Almost all reports conceded that the overall obesity rates remained unchanged, based on this latest U.S. study, but the CDC (Centers for Disease Control) data, published in the February 26 issues of Journal of the American Medical Association appeared to showcase this first time decline of obesity rates, in a specific age group.  The forty three percent decrease in the two to five year old population was certainly lauded as overdue and hopeful. 

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    Prior to this new study, a report from the CDC had seemed to show that in low-income children participating in the federal nutrition program, there had been a decline in obesity.  It was also suggested that in particular cities including Anchorage, New York City, Philadelphia and King County, Washington, obesity programs appeared to be having a beneficial impact on younger children’s health and weight.  Certainly there has been an effort by some daycare centers to improve the nutrition profiles of the foods being served, to increase physical activity and overall fitness, and there has also been an overall effort to curb consumption of sweetened beverages and improve breastfeeding rates – all of which would be considered measures that impact and lower rates of obesity.  Certainly First Lady Michelle Obama has made childhood obesity her main focus, leading some to wonder if there is already an impact from her efforts on the weight of young children.


    Now some experts, who noted the sensational coverage of this study, are saying that there was a pretty poor effort to really look at the statistical facts, and little attention paid to the deeper analysis of the study itself.  So how did the media outlets and some experts get the interpretation of the facts so wrong?  Well it appears that (a) there may be a statistical error or fluke in the forty three percent conclusion, because other similar studies did not showcase this astounding statistic (b) initial robust skepticism was missing when health professionals and reporters viewed the findings that appear to be nothing less than astounding (remember that no other age group has shown anywhere near a measurable improvement in obesity statistics over the same time period) (c) there really isn’t any good explanation to support the huge drop in preschool rates of obesity, since many of the habits used to explain the outcome, even when combined, might only nudge weight down in small increments (d) the size of the pool of subjects in the study was really small – 871 to be exact – which allows for more rather than fewer margins of error.


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    Even the CDC suggested that there were “statistical limitations to the data and findings," and the CDC study's authors admit to rounding the finding of forty percent to forty three percent, and also sharing that there was enough margin of error to have the real statistical finding closer to as low as a change rate of 10.8 percent to a high of 17.6 percent.  That's quite a distance from forty three percent!  In fact, there may actually have been no change at all in the preschooler obesity rates if you precisely overlap the years 2003-2004 with 2011-2012.  What’s even worse?  There may have actually been a slight increase in obesity rates among these very young children, if you look at the “bounce around” rates of obesity during the last decade.  If you look examine habits that changed in the last ten years:

    • TV viewing time rose
    • Consumption of sweet and salty treats rose
    • Fruit and vegetable consumption fell
    • Physical activity did rise a bit, but not dramatically
    • Programs like healthier school lunches, vending machine swap outs, the Let’s Move campaign, all targeted older children, so a change in their obesity rates should have been noted and it wasn’t.


    The moral of the story may be that media does often grab on to certain elements of a study or story, without fully flushing out the facts.  This will often happen when the deadlines can be sensational.  In this case, the forty three percent decrease in preschoolers’ obesity rates may just be “too good to be true.”


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    Amy Hendel is a Physician Assistant and Health Coach with over 20 years of experience.  Noted author, journalist and lifestyle expert, she brings extensive expertise to her monthly shareposts.  Her most recent book, The 4 Habits of Healthy Families is available for purchase online, and you can watch her in action on her shows Food Rescue and What's for Lunch?  Sign up for her daily health tweets or catch her daily news report at


Published On: March 18, 2014